Two days ago, I received a 13-day prison sentence for my role in a 2009 protest outside Britain's military nerve centre in Northwood against the bombing of Afghanistan. When I was in Afghanistan earlier this year I met a young man whose sister had been left widowed, with an infant son, by a Nato air strike that killed five civilians. Meeting the victims of our government's policies has only strengthened my conviction that we need to end Britain's role in this senseless and bloody war. But despite a "game-changing" move by the Taliban towards peace talks, with the opening of its political office in Qatar (Taliban peace talks 'at risk' as Obama stalls on Guantánamo, 18 January), the US looks committed to continuing its war in Afghanistan – albeit retooled to place more emphasis on drones, special forces and local proxies. Those of us who want to see British troops withdrawn – a sizable majority, according to the polls – must seize this crucial moment to force the US to the negotiating table.Maya EvansHMP Bronzefield, Ashford, Middlesex